Right angle
A right angle was a type of angle that measured 90°. A triangle with a right angle in it was called a right triangle
In 2257, Christopher Pike told the computer to rotate an image of signals provided by Starfleet by 90° counterclockwise and found it nearly matched a drawing done by Spock. (DIS: "New Eden")
Brad Boimler told Taylor he had to reach for power cylinders at a 90° angle, not 80. (LD: "In the Cradle of Vexilon")